Sibling relationships are a unique and special bond throughout the life span. Having a sibling with autism may present extra difficulties to form a close and meaningful relationship. While siblings play an important role in the child with Autism Spectrum Disorder (ASD) life, there is no consistent method for involving siblings in treatment for individuals with ASD. This current study evaluated a novel treatment package including training siblings on play strategies (called play tips when communicating with the participants) in combination with a sibling support group to increase positive sibling play and perceived relationship quality. Using two concurrent multiple baseline designs, nine sibling dyads participated in the online STEPS program. Specifically, the intervention package included an online implementation of behavior skills training on simple play strategies and participation in a sibling support group. The intervention package improved quality of sibling play and increased the perceived quality of the sibling relationship. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]